Collaborative Research: REVEALING STRUCTURE-IONIC TRANSPORT RELATIONSHIP IN POLYMER-IONIC LIQUID IONOGELS

With support from the Chemical Structure and Dynamics (CSD) program in the Division of Chemistry, Professors Pinar Akcora of the Stevens Institute of Technology and Jindal Shah of Oklahoma State University will combine experimental and computational techniques to study the motion of ions in mixtures of ionic liquids and polymers, called ionogels. Ionic liquids are solvents comprised solely of ions. When combined with polymers at high concentrations, the interactions between the ions and the polymer cause the structure of the mixture at a molecular level to be nonuniform, potentially giving rise to ionic conductivity gradients. Professors Akcora, Shah, and their students will combine neutron spectroscopy and dielectric spectroscopy with atomistic simulations to link polymer-ionic liquid interactions with ion distribution and ion transport in ionogels. Their discoveries could provide ways to regulate conductivity with potential applications in ionotronics, sensors and biomedical devices that require strength, conductivity and flexibility. The project will provide research opportunities for graduate students, as well as planned outreach activities for students of all ages, which will promote scientific curiosity and contribute to the development of a STEM workforce. This project will use neutron scattering and dielectric spectroscopy measurements coupled with atomistic simulations to explore the structure and dynamics of mixtures of uncharged and charged polymers with ionic liquids. The ion distribution and conformation of ionic gels will be explored to interrogate the role of dynamic heterogeneities in the system. These studies will allow us to identify molecular origins underlying nonuniform swelling, crosslinking and structure-dependent ion transport in ionogels. The specific objectives are to understand the role of ion-dipole interactions on chain conformations in polymers differing in chemistries; determine the relationship between ion correlations and ionic transport; analyze the field-induced ion distribution in gels; and measure and simulate the ion distributions within ionic liquid and polymer brush interphases. Understanding the structure and dynamics in gels will enable the design of novel structured ionogels that could have implications for applications in sensing and biomedicine. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.